1.What Is The Working Time For Street Lights?
The ideal working time for street lights are that, turn on the street lights around 30 minutes before sunset, and turn off around 30mins before dawn.
But since the road situation, the location and seasons are different, so the working time for street lights are customized based on city policies and public municipalities, and will depend on the road grade where the street lights are used.
2.Who Controls Street Lights Turn On And Turn Off?
Typically the local government and municipality are responsible for the operation and maintenance of street lights, including the working plan on and off time for street lights. In most cities, the tasks are outsourced to some construction companies or private companies.
3.How To Control On and Off For Street Lights?
Regularly, street lights are all turn off automatically, because turning on and off by human control are too time wasting and inconvenient.
There are some different ways to control on and off for street lights.
3.1 By Using Photo-resistor or Photocell
Photocell is a daylight senor and is widely used in LED street lights. It helps the lights turn on and off automatically based on the amount of the light shining on it.
When there is enough sunshine, the photocell has low resistance and will stop the supply or electricity. While when it is dark, the photocell will have high resistance and will allow the electricity to pass through.
Advantage for photocell: It is controlled by light control, so it will adjust the working plan based on different seasons, and different weather conditions. When it is cloudy or rainy, it will turn on automatically because it senses the illumination is low.
Disadvantage for photocell: The streets are always full of dust, so the photocell elements may be covered with dust, and making itself inaccurate.
3.2 By Using Time Control
Time control means we can set the working program for the streetlights, and the street lights will turn on and off based on our setting. Regularly the working program will be set based on sunset and sunrise time.
Advantage of time control is that the whole system is very stable, and the whole working plan is very accurate, not too many accidents will happen.
The disadvantage of time control is that when it is rainy or cloudy, the street lights can not be automatically turned on. Also in summer, the sunrise is earlier compared to winter, and the sunset is later. And the working time of streetlights also need to be advanced or postponed accordingly. In this case, we will need human work to change the working plan when new seasons come, or else it will result in not sufficient light or waste of energy.
3.3 By Using Motion Sensor
Motion sensors for street lights are using infrared technology to monitor the movement with a certain range. The working theory is that they will release the infrared light and when there is something passing through, there will be a reflect of beam to the sensor. And this reflecting beam will start the sensor and initiate the street lights to switch on.
Advantage: It is very energy saving and flexible. The sensitivity and distance of the sensor can be adjusted based on the location and different lighting requirement. And by switching off when there’s no movement, it is a big reduction for energy consumption.
Disadvantage: This motion sensor can only be used in the places without too many car flows, like countryside roads, or village roads. If use it for main road, the coming and going cars will make the motion sensors to turn on the street lights and turn off the street lights all the time, which will be a very bad experience for the drivers and people passing by.
4.Why Are Street Light On During The Day?
If the street lights are on during the day, there are several main reasons.
- Failure: The electrical system for the street lights is not working, so the lights is working during day light. In this case, we report this problem to related departments.
- Maintenance or Fixing: The streetlights maintenance regularly is done during the daytime. And by turning on all the street lights, the maintenance people can pinpoint which lights have failures and avoid the risk electrocution.
- Weather conditions: If it is rainy or cloudy, for the street lights with photocells, they will be turned on automatically to provide enough light.
- Vandalism and Theft: Sometimes, keeping the lights on in the day time is to discourage the vandalism and cable theft. This is not regular, because turning on the lights in daytime is a waste of electricity.
5. For Solar Street lights, Who Controls The On And Off ?
For solar street lights, the on and off is controlled by the light control in the whole solar system. This means that, when the solar system feels there is not enough sunshine, it will turn on the lights. And if there is enough sunshine, it will turn off the lights.
The regular light control is realized by photocells, while in solar street light system, there is no photocell. The sense of the sunshine is realized by the solar panel. When there is enough sunshine, the solar panel will sense high voltage and starts to charge the battery through controllers, and the controller will order solar street lights to turn off.
And if the sunshine is not strong, the solar panel will sense lower wattage and stops charging and the controller will order the solar street lights to turn on.
6.Conclusion
If you are wondering how does street lights know when to turn on and off, and if you are wondering who controls on and off for the street lights, I hope this article can give you the answers.
Street lights are every importance for the whole city system, so a smart and environmental street light solutions are vital.
7.Amber Provides All Kinds Of Streetlight Solutions
As a professional street light manufacturers with over 10 years experience, Amber is providing all kinds of street lights, street lights poles, and street light smart solutions include light control, time control or dimming. We can give the most professional and best suggestion and design for your street light projects.